Today, an old man writes his most important book. The
University of Houston's College of Engineering presents
this series about the machines that make our civilization
run, and the people whose ingenuity created them.

I've just finished Dava Sobel's new
book, Galileo's Daughter. Sobel describes the
intense affection between Galileo and his semi-legitimate
daughter. Born Virginia, she became a nun in the San
Mateo cloister, near Florence, and took the name of Maria
Celeste.

Sobel's powerful account tells how Galileo did all his
science in close concert with his Church, and it reveals
the sustaining force of Maria Celeste's letters. That
sustenance was especially important after Galileo's
former friend, Pope Urban VIII, turned upon his book,
Dialogue Concerning the Two Chief World Systems.
As punishment, Galileo was placed under house arrest.

Aging, depressed, and exhausted from his trial, Galileo
was sent back to northern Italy and confined at the
Archbishop's residence in Siena. The Pope finally decided
that Galileo had access to too many people there and
removed him to his small house near the cloister, where
he, like his daughter, would live in isolation.

The two world systems in Galileo's book had been the new
Sun-centered Copernican world and the old Earth-centered
Ptolemaic one. His trial had revolved around the
question: Was he presenting the Sun-centered system as a
hypothesis or as a fact? The Inquisition decided that the
characters in the book presented far too convincing an
argument that Earth really does revolve around the Sun --
that Galileo took Earth's motion to be no mere
hypothesis.

The book got loose outside Italy, and it forcefully
argued Copernicus' case. But, despite its huge impact,
Galileo's most important work was yet to come. While he
was under house arrest with his old friend, the
archbishop of Siena, Galileo began work on his last book,
Two New Sciences, about materials science and
dynamics.

But then Galileo was sent back to his house near Maria
Celeste, only to see her die a few months later. Galileo
was inconsolable. A total immersion in the Two New
Sciences was his only means for coping with terrible
grief.

And so Galileo laid out the foundations of modern
engineering. He set the stage for Isaac Newton, who was
born the same year he died. The aging Galileo gave us the
beginnings of beam theory. He sketched out the notion of
similitude theory when he showed that a large animal
cannot be the scaled-up version of a smaller animal. He
published his famous law of the pendulum for the first
time. He explained the trajectories of projectiles.

Here Galileo emerges from humiliation and grief
completely freed from Aristotle's old science. He writes
upon a clean slate as he creates modern mechanics. To get
his book published Galileo lent the manuscript out of
Italy and then claimed not to've given permission for its
publication. Ironically, one clandestine visitor to his
house was John Milton, who would later do his own best
work in prison. And I must say: I find the liberating
power of adversity to be one of the more disquieting
facts of life.

I'm John Lienhard, at the University of Houston, where
we're interested in the way inventive minds work.

(Theme music)

Sobel, D., Galileo's Daughter. New York: Penguin
Books, 1999.

Galileo, G., The Two New Sciences by Galileo
Galilei. (Tr. by Henry Crew and Alfonso de Salvio.)
Evanston,IL: Northwestern University Press,
1914/1933/1939.